Wafer-Level Packages (WLPs) are known as an example of semiconductor packages (semiconductor devices) that include semiconductor elements such as bare chips. WLPs are also referred to as Wafer-Level Chip Size Packages (WL-CSPs) or Wafer-Chip Size Packages (W-CSPs). WLPs allow terminals at the ends of a bare chip to be relocated in a chip area, that is, to be fanned-in. WLPs that allow the terminals to be relocated out of the chip area, that is, to be fanned-out, have also been developed in light of a situation in which relocation of the terminals only in the chip area has become difficult because of the increasing number of terminals per bare chip.
In a known technology, such semiconductor packages are manufactured in a method as follows: a semiconductor elements are bonded onto an adhesive layer such as an adhesive sheet provided on a support body, the semiconductor elements are sealed with resin so as to form a dummy wafer, and the dummy wafer is removed from the adhesive layer. In order to remove the dummy wafer from the adhesive layer, the adhesive force of the adhesive layer is decreased by, for example, ultraviolet radiation, chemical treatment, or heat treatment. When the dummy wafer is removed from the adhesive layer, a wiring layer is formed in the dummy wafer, and the dummy wafer is diced into singulated semiconductor packages.
In a known related-art technology for resin sealing using a mold that includes an upper and lower dies, the lower die has irregularities and ejector pins. The irregularities are formed in a surface of the lower die so as to suppress adhesion of a sealed package, and ejector pins are used to remove the package out of the mold.
Examples of related art include the following patent documents:    Description of U.S. Pat. No. 7,202,107B2;    Japanese Patent No. 4403631;    Japanese Laid-open Patent Publication No. 2011-134811; and    Japanese Laid-open Patent Publication No. 2000-133666.
In a technology as described above, in which the dummy wafer (substrate) having been formed on the adhesive layer is removed from the adhesive layer, a technique is usable, in which the adhesive force of the adhesive layer is decreased by ultraviolet radiation, chemical treatment, or heat treatment performed on the adhesive layer.
However, such an adhesive layer, the adhesive force of which is decreased as described above, is difficult to reuse. Thus, the adhesive layer to use is replaced every time a dummy wafer is formed, thereby obstructing reduction in time and cost taken to manufacture semiconductor devices (semiconductor packages). Furthermore, use of thus manufactured semiconductor devices may increase the cost of electronic assemblies.